1. Field of the Invention
The present invention relates generally to air handling systems within automotive vehicles. More particularly, the present invention relates to a center-mounted air handling system having a novel arrangement of temperature controlled blend doors having coordinated movements.
2. Disclosure Information
Many different types of air handling systems are well-known within the automotive vehicle art. The most commonly known air handling system typically includes a housing having a centrifugal blower which draws in fresh or recirculation air and discharges outlet air through the housing of the system. Disposed within the system are a pair of heat exchangers, one for the cooling the air leaving the centrifugal blower and the other for heating the air leaving the centrifugal blower. A blend door or system of blend doors are provided within the housing at key locations to control the amount of air flow through either or both of the heat exchangers to provide conditioned air into the interior passenger compartment of the vehicle. Typically, a vehicle occupant will adjust a temperature control knob within the interior of the vehicle to a desired setting which triggers the movement of the temperature control blend doors to predetermined positions. These positions are selected to provide a proper amount of cooled and heated air to meet the occupant's requested temperature selection.
Various technological improvements have been proposed to the known types of air handling systems, such as to provide dual temperature systems as well as dual temperature and mode systems. In these types of systems different temperatures can be provided to different areas within the interior compartment of the vehicle. Moreover, the conditioned air can be delivered from different outlets within the passenger compartment such as for heating the floor or defogging of the windshield. U.S. Pat. No. 5,673,964, assigned to the assignee of the present invention, discloses a unique air handling system which can be mounted generally along a center line of the vehicle to accommodate either a right hand drive or left hand drive vehicle. In order to accommodate this type of flexibility, the packaging of such an air handling system requires that the heat exchangers be in very close proximity to one another. Because of the small packaging characteristics of such a system, there is a very short duct length from the outlet of the air handling system to the interior passenger compartment of the vehicle. This short passageway may not provide enough volume for proper mixing of the air in the system to provide the appropriate temperature selected or requested by the vehicle occupant. For example, more air may be passed through an evaporator around a blend door than is necessary for a selected temperature. This would perhaps provide an incorrect temperature of conditioned air to discharge from the outlet registers of the air handling system. It would therefore be advantageous to provide an air handling system which allows for smaller packaging but overcomes the problems of the prior art in terms of the available volume for appropriate mixing of the warm and cool air.
It is an object of the present invention to provide a center-mounted air handling system with a temperature blend door system which provides proper mixing of the cool air and warm air prior to or to ensure the correct discharge temperature of air from the system registers.
It is a further object of the present invention to provide a blend door system having coordinated movement to provide correct discharged temperature air as requested by a vehicle occupant.